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authorAndrew Vagin <avagin@openvz.org>2012-11-15 04:03:17 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 12:14:19 -0800
commitc6f7b86211233142300aeec7b1ab4ae640b81abd (patch)
tree5b8f0580777fc714b9dd1597ee1bac61da701011 /net
parenta809dffbbbcfbac5f6e6e291e472ac3ca91e0ca2 (diff)
tcp: fix retransmission in repair mode
[ Upstream commit ec34232575083fd0f43d3a101e8ebb041b203761 ] Currently if a socket was repaired with a few packet in a write queue, a kernel bug may be triggered: kernel BUG at net/ipv4/tcp_output.c:2330! RIP: 0010:[<ffffffff8155784f>] tcp_retransmit_skb+0x5ff/0x610 According to the initial realization v3.4-rc2-963-gc0e88ff, all skb-s should look like already posted. This patch fixes code according with this sentence. Here are three points, which were not done in the initial patch: 1. A tcp send head should not be changed 2. Initialize TSO state of a skb 3. Reset the retransmission time This patch moves logic from tcp_sendmsg to tcp_write_xmit. A packet passes the ussual way, but isn't sent to network. This patch solves all described problems and handles tcp_sendpages. Signed-off-by: Andrey Vagin <avagin@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_output.c4
2 files changed, 6 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 49dd9930781..b0b39f60495 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1236,7 +1236,7 @@ new_segment:
wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
- if (copied && likely(!tp->repair))
+ if (copied)
tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
@@ -1247,7 +1247,7 @@ wait_for_memory:
}
out:
- if (copied && likely(!tp->repair))
+ if (copied)
tcp_push(sk, flags, mss_now, tp->nonagle);
release_sock(sk);
return copied + copied_syn;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d04632673a9..6735beaacbe 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1977,6 +1977,9 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
BUG_ON(!tso_segs);
+ if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE)
+ goto repair; /* Skip network transmission */
+
cwnd_quota = tcp_cwnd_test(tp, skb);
if (!cwnd_quota)
break;
@@ -2017,6 +2020,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp)))
break;
+repair:
/* Advance the send_head. This one is sent out.
* This call will increment packets_out.
*/